Method for Producing Ink Jet-Recorded Matters and Apparatus for Producing Ink Jet-Recorded Matters

The present invention relates to a method for producing ink jet-recorded matters and an apparatus for producing ink jet-recorded matters.

Ink jet recording apparatuses are apparatuses that eject minute ink droplets from an ejection orifice of a recording head to record images on recording media. In recent years, the use of ink jet recording apparatuses has been considered in the field of signs & displays, such as printing posters and giant advertisements, as well as in the field of label printing and package printing. Ink jet recording apparatuses are required to be able to record images on a wide range of recording media, including not only recording media that absorb aqueous inks but also non-absorbent recording media that hardly absorb aqueous inks. Examples of the non-absorbent recording media that hardly absorb aqueous inks include resin films.

Recorded matters obtained by recording images on recording media are subjected to processing such as cutting and clipping depending on the intended application to become final products. For example, when used as product labels, in recorded matters having a support with an image recorded thereon, an adhesive layer and release paper, the surroundings of the portion to be used as a product label are half-cut. Then, the portion not used as a product label may be removed from the release paper, so-called stripping, to make the final product. As a method for cutting recorded matters, a laser die cutting method has been attracting attention in recent years. The laser die cutting method is a method that uses a high power laser to cut objects. In the case of a mechanical die cutting method, it is necessary to fabricate a die that matches the shape to be cut out. In contrast, the laser die cutting method cuts recording media by direct irradiation with a laser while controlling the cut shape with a computer, thus eliminating the need to fabricate a die. In addition, the laser beam can be controlled very finely, making it easy to cut into complicated shapes.

For example, a method for processing label paper is proposed in which a cut track and a printing pattern are each printed on the label paper along the contour of a die cutting shape using a black ink, and then the paper is half-cut by irradiation with laser light so as to trace the cut track (Japanese Patent Application Laid-Open No. 2014-218040).

The present invention is directed to the provision of a method for producing ink jet-recorded matters that enables production of high quality recorded matters with narrowly and uniformly aligned cut widths when cutting a resin film-containing recording medium on which an image has been recorded by an ink jet system by a laser die cutting method, and an apparatus for producing ink jet-recorded matters.

That is, according to one aspect of the present invention, a method for producing ink jet-recorded matters is provided, having a step of applying an aqueous reaction liquid to a resin film-containing recording medium, a step of applying an aqueous ink by an ink jet system so as to overlap at least a portion of a region of the recording medium to which the reaction liquid has been applied, thereby recording an image, and a step of irradiating a region to which the reaction liquid and the aqueous ink have been applied with laser light to cut the recording medium, wherein the reaction liquid contains an inorganic metal salt, and the aqueous ink contains titanium oxide.

In addition, according to another aspect of the present invention, an apparatus for producing ink jet-recorded matters is provided, having a reaction liquid applying device that applies an aqueous reaction liquid to a resin film-containing recording medium, an ink applying device that applies an aqueous ink by an ink jet system so as to overlap at least a portion of a region of the recording medium to which the reaction liquid has been applied, thereby recording an image, and a laser light irradiating device that irradiates a region to which the reaction liquid and the aqueous ink have been applied with laser light to cut the recording medium, wherein the reaction liquid contains an inorganic metal salt, and the aqueous ink contains titanium oxide.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Hereinafter, the present invention will be described in further detail with reference to preferred embodiments. In the present invention, if a compound is a salt, the salt is dissociated into ions in the ink, but the expression “salt is contained” is used for convenience. Also, an aqueous ink and a reaction liquid for ink jet may be described simply as an “ink” and a “reaction liquid”, respectively. Physical property values are those at normal temperature (25° C.), unless otherwise noted. The description “(meth)acrylic acid” and “(meth)acrylate” means “acrylic acid and/or methacrylic acid” and “acrylate and/or methacrylate”, respectively.

The present inventors have studied the processing method proposed in Japanese Patent Application Laid-Open No. 2014-218040. Specifically, an image was recorded on a resin-film using a color ink and a white ink, and a cut track (cut region) along the contour of a die cutting shape was also recorded using a black ink. Then, using a laser die cutting apparatus, the film was half-cut along the cut track by irradiation with laser light. As a result, it was found that a variation in cut width was likely to occur and cut width became larger than a spot diameter of the laser light because the cut track to which the black ink was applied was damaged by the laser light. It was also found that, when cutting by the laser die cutting method without recording the cut track, a variation in cut width also occurred and cut width became larger than a spot diameter of the laser light. Furthermore, it was found that there was a difference between the cut width of a printed part to which the white ink had been applied and the cut width of a printed part to which only the color ink had been applied and an unprinted part to which no ink had been applied. In this manner, if there is an expansion or a variation in cut width, the edges formed by cutting will not be neatly aligned, and the appearance of the resulting recorded matters will be spoiled.

Therefore, the present inventors have conducted diligent studies on a method for producing ink jet-recorded matters that enables production of high quality recorded matters with narrowly and uniformly aligned cut widths when cutting a resin-containing recording medium on which an image has been recorded by an ink jet system by a laser die cutting method, and an apparatus for producing ink jet-recorded matters to complete the present invention.

According to the studies by the present inventors, it was found that, when a resin film-containing recording medium on which an image has been recorded is cut by the laser die cutting method, an expansion or a variation is likely to occur between (i) the cut width of a printed part (a white ink application region) to which the white ink has been applied and (ii) the cut width of a printed part (a color ink application region) to which the color ink has been applied and an unprinted part (an ink non-application region) to which no ink has been applied. The present inventors presume the reason why such an expansion or a variation is likely to occur as follows.

The decomposition temperature of titanium oxide used as a coloring agent in white inks is as high as about 2,000° C., and thus, it tends not to be burned out easily when heated by irradiation with laser light, resulting in a narrower cut width. On the other hand, resin films, and organic pigments and carbon black used as coloring agents in color inks and black inks tend to burn and disappear easily when heated by irradiation with laser light, resulting in a wider cut width. Therefore, it is presumed that an expansion or a variation is likely to occur between (i) the cut width of a printed part to which the white ink has been applied and (ii) the cut width of a printed part to which the color ink has been applied and an unprinted part.

The present inventors have conducted studies on a method that can suppress the occurrence of expansion and variation in cut width, even if a resin film-containing recording medium on which an image has been recorded by applying a white ink and a color ink is cut by the laser die cutting method. As a result, they have found the configuration of the present invention, which will be shown below. That is, in the method for producing ink jet-recorded matters of the present invention, an image is recorded by applying an aqueous reaction liquid containing an inorganic metal salt and an aqueous ink containing titanium oxide to a resin film-containing recording medium by an ink jet system. Then, a region to which the reaction liquid and the aqueous ink have been applied is irradiated with laser light to cut the recording medium. By applying in advance the reaction liquid containing an inorganic metal salt and the ink containing titanium oxide to the region to be cut by irradiation with laser light, it is considered that thermal deformation and other problems of the resin film contained in the recording medium caused by laser light irradiation can be suppressed and the occurrence of expansion and variation in cut width can be suppressed. In addition, by allowing the reaction liquid containing an inorganic metal salt to aggregate the ink containing titanium oxide, the amount of titanium oxide present in the region to be cut can be uniformly controlled. This enables high quality recorded matters with narrowly and uniformly aligned cut widths to be obtained. On the other hand, if a color ink containing an organic pigment or a black ink containing carbon black is applied to the region to be cut by irradiation with laser light without applying a white ink containing titanium oxide, the difference in deformation amount caused by laser light irradiation cannot be suppressed, and thus, it is considered to be difficult to suppress the occurrence of expansion and variation in cut width.

The method for producing ink jet-recorded matters of the present invention has a reaction liquid applying step, an image recording step, and a step of irradiating a region to which a reaction liquid and an aqueous ink have been applied with laser light to cut a recording medium. In the reaction liquid applying step, an aqueous reaction liquid is applied to a resin film-containing recording medium. In the image recording step, an aqueous ink is applied by an ink jet system so as to overlap at least a portion of a region of the recording medium to which the reaction liquid has been applied, thereby recording an image. Then, the reaction liquid contains an inorganic metal salt, and the aqueous ink contains titanium oxide.

Also, the apparatus for producing ink jet-recorded matters of the present invention has a reaction liquid applying device, an ink applying device and a laser light irradiating device. In the reaction liquid applying device, an aqueous reaction liquid is applied to a resin film-containing recording medium. In the ink applying device, an aqueous ink is applied by an ink jet system so as to overlap at least a portion of a region of the recording medium to which the reaction liquid has been applied, thereby recording an image. In the laser light irradiating device, a region to which the reaction liquid and the aqueous ink have been applied is irradiated with laser light to cut the recording medium. Then, the reaction liquid contains an inorganic metal salt, and the aqueous ink contains titanium oxide.

Hereinafter, the details of the method for producing ink jet-recorded matters and apparatus for producing ink jet-recorded matters of the present invention (hereinafter, also referred to as “method for producing recorded matters” and “apparatus for producing recorded matters”, respectively) will be described.

Hereinafter, the details of an ink jet recording apparatus used in the method for producing recorded matters will be described with reference to drawings.is a schematic diagram illustrating an example of the ink jet recording apparatus. The ink jet recording apparatus that can be used in the method for producing recorded matters of the present invention is an ink jet recording apparatus that uses a reaction liquid containing a reactant that reacts with inks, a first ink and a second ink to record an image on a recording medium wound in the form of a roll. The X direction, Y direction and Z direction represent the width direction (full length direction), depth direction and height direction of the ink jet recording apparatus, respectively. The recording medium is conveyed in the X direction.

An ink jet recording apparatusillustrated inis configured to have a first recording section, a first heating section, a first cooling section, a second recording section, a second heating section, a second cooling sectionand a take-up section. In the first recording section, various liquids including the first ink are applied by a first liquid applying deviceto a long recording mediumthat is conveyed from a paper feeding devicewhile being supported by a conveying member. In the first heating section, the recording mediumis placed along a first conveying memberto maintain tension, while the liquids that have been applied to the recording mediumare heated by a first heating deviceto evaporate volatile components such as moisture in the liquids to dryness. Thereafter, the recording mediumis cooled by a first cooling memberwhile being supported by a first conveying memberof the first cooling section.

Next, in the second recording section, various liquids including the second ink are applied by a second liquid applying devicein the same manner as for the case of the various liquids including the first ink. In the second heating section, the recording mediumis placed along a second conveying memberto maintain tension, while the liquids that have been applied to the recording mediumare heated by a second heating deviceto evaporate volatile components such as moisture in the liquids to dryness. Next, the recording mediumis cooled by a second cooling memberwhile being supported by a second conveying memberof the second cooling section. The recording mediumon which an image has been recorded is conveyed while being supported by a supporting memberin the take-up section, and then taken up by a take-up device.

As the recording medium, a resin film-containing recording medium is used. The resin film-containing recording medium may be composed of only the resin film, or may contain materials other than the resin film such as an adhesive paper or release paper. When the recording medium contains materials other than the resin film, the resin film is preferably disposed on the surface of the recording medium. Examples of the resin constituting the resin film include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene and polypropylene. The resin film may be transparent or opaque. Also, the resin film may contain a colorant. Generally, when recording media containing a transparent resin film that are free from inorganic materials are used, a difference in deformation amount when irradiated with laser light is likely to occur between a printed part to which a white ink has been applied, and a printed part to which a color ink has been applied and an unprinted part, and an expansion or a variation in cut width is particularly noticeable. In contrast, according to the method for producing recorded matters of the present invention, even when using transparent recording media that are free from inorganic materials, high quality recorded matters with narrowly and uniformly aligned cut widths can be produced. The basis weight (g/m) of the recording mediumis preferably 30 g/mor more to 500 g/mor less, and more preferably 50 g/mor more to 450 g/mor less. Examples of the recording mediuminclude rolled paper formed by winding a long recording medium or sheet paper.

The recording section is configured to have the first recording section, which applies liquids including the first ink, and the second recording section, which applies liquids including the second ink. The first recording sectionhas the first liquid applying device. The first liquid applying deviceis configured to have a first reaction liquid applying deviceand a first ink applying device. The second recording sectionhas the second liquid applying device. The second liquid applying deviceis configured to have a second reaction liquid applying deviceand a second ink applying device. The first reaction liquid applying deviceand the second reaction liquid applying deviceillustrated inare examples of units using ejection head in an ink jet system. The reaction liquid applying devices may also be configured utilizing a gravure coater, an offset coater, a die coater and a blade coater, among others. The application system of the first reaction liquid applying deviceand the second reaction liquid applying devicemay be the same or may be different. Application of the reaction liquid by the first reaction liquid applying deviceand the second reaction liquid applying devicemay be performed either before or after ink application, as long as the reaction liquid can be in contact with the ink on the recording medium. However, in order to record high quality images on a variety of recording media with different liquid absorption characteristics, it is preferable to apply the reaction liquid before application of the ink. As the first ink applying deviceand the second ink applying device, ejection heads (recording heads) in the ink jet system are used. Examples of the ejection system of ejection heads as the first liquid applying deviceand the second liquid applying deviceinclude a system in which liquid is allowed to undergo film boiling by an electro-thermal converter to form bubbles, thereby ejecting the liquid, and a system in which liquid is ejected by an electro-mechanical converter. The ejection system of the first ink applying deviceand the second ink applying devicemay be the same or may be different. Also, the first reaction liquid used in combination with the first ink and the second reaction liquid used in combination with the second ink may be the same or may be different. When the recording medium is laminated with a material other than a resin film such as an adhesive layer or release paper, the reaction liquid, the first ink and the second ink are applied to the surface of the recording medium on which the resin film exists.

The first liquid applying deviceand the second liquid applying deviceare line heads extended in the Y direction, and ejection orifices are arranged in the range covering the image recording region of the usable recording medium with the maximum width. The ejection head has an ejection orifice surface() on which ejection orifices are formed on its lower side (on the recording mediumside), and the ejection orifice surface faces the recording mediumwith a minute distance of a few millimeters.

Hereinafter, description will be given using the case where the first ink (white ink) is ejected from the first ink applying deviceand the second ink (non-white ink) is ejected from the second ink applying deviceas an example. There may be a plurality of second ink applying devicesprovided in order to apply inks of various colors to the recording medium. For example, if using a yellow ink, a magenta ink, a cyan ink and a black ink as the second ink (non-white ink) to record an image of each color, four second ink applying devicesthat eject the above four inks are disposed side by side in the X direction. The color tone of the first ink and the second ink is not limited to the above, and the application order of each ink is not limited to the above either. Hereafter, the ink and the reaction liquid are sometimes collectively referred to as “liquid”.

is a perspective view illustrating an example of the liquid applying device. Since the first liquid applying deviceand the second liquid applying devicecan have the same configuration, hereinafter, description will be given using the first liquid applying deviceas an example. The first liquid applying deviceillustrated inis a line head, with a plurality of ejection element substratesarranged in a linear fashion, on which ejection orifice arrays are provided. On the ejection element substrates, a plurality of ejection orifice arrays is arranged.

is a cross-sectional perspective view illustrating an example of the ejection element substrate. The ejection element substrateillustrated inhas an ejection orifice forming memberon which ejection orificesare opened, and a substrateon which ejection elements (not illustrated) are disposed. Lamination of the ejection orifice forming memberand the substrateforms a first flow pathand a second flow paththrough which the liquid flows. The first flow pathis the region from an inlet, where the liquid flows in from an inlet path, to the portion between the ejection orificeand the ejection element (, liquid chamber). Also, the second flow pathis the region from the portion between the ejection orificeand the ejection element (, liquid chamber) to an outlet, where the liquid flows out to an outlet path. For example, by providing a pressure difference between the inletand the outlet, such as the inletwith a higher pressure and the outletwith a lower pressure, the liquid can be made to flow from the higher pressure to the lower pressure (in the direction of the arrows in). The liquid that has passed through the inlet pathand the inletenters the first flow path. Then, the liquid through the portion between the ejection orificeand the ejection element (, liquid chamber) flows through the second flow pathand the outletto the outlet path.

is a schematic diagram illustrating an example of a supply system for the liquid such as ink. A supply sectionof the first liquid applying deviceillustrated inis configured to have a first circulation pump (high pressure side), a first circulation pump (low pressure side), a sub tank, and a second circulation pump. The sub tank, which is connected to a main tank, liquid storage section, has an atmospheric communication port (not illustrated), which allows air bubbles mixed in the liquid to be discharged out of the circulation system. The sub tankis also connected to a refill pump. The liquid is consumed in the first liquid applying deviceby ejecting (discharging) the liquid from the ejection orifices, such as by recording an image or by suction recovery. The refill pumptransfers the liquid corresponding to the amount consumed from the main tankto the sub tank.

The first circulation pump (high pressure side)and the first circulation pump (low pressure side)allow the liquid in the first liquid applying devicethat has flowed out of a connection section (inlet section)to flow into the sub tank. As the first circulation pump (high pressure side), the first circulation pump (low pressure side)and the second circulation pump, it is preferable to use positive displacement pumps, which have a quantitative liquid delivery capacity. Examples of such positive displacement pumps include a tube pump, a gear pump, a diaphragm pump and a syringe pump. At the time of driving the ejection element substrate, the liquid is allowed to flow from a common inlet pathto a common outlet pathby the first circulation pump (high pressure side)and the first circulation pump (low pressure side).

A negative pressure control unithas two pressure regulating mechanisms with different control pressures set for each other. A pressure regulating mechanism (high pressure side)and a pressure regulating mechanism (low pressure side)are connected to the common inlet pathand the common outlet pathin the ejection element substratevia a supply unitprovided with a filterto remove foreign matter from the liquid, respectively. The ejection element substratehas the common inlet path, the common outlet pathand the inlet pathand the outlet path, which are in communication with the liquid chamber, portion between the ejection orifice() and the ejection element (not illustrated). Since the inlet pathand the outlet pathare in communication with the common inlet pathand the common outlet path, respectively, a flow (arrows in) occurs in which a portion of the liquid flows from the common inlet paththrough the inside of the liquid chamberto the common outlet path. The arrows inindicate the flow of liquid inside the liquid chamber. That is, as illustrated in, the liquid in the first flow pathflows into the second flow pathvia the space between the ejection orificeand the ejection element.

As illustrated in, the pressure regulating mechanism (high pressure side)is connected to the common inlet pathand also the pressure regulating mechanism (low pressure side)is connected to the common outlet path, resulting in a pressure difference between the inlet pathand the outlet path. This also generates a pressure difference between the inlet(), which is in communication with the inlet path, and the outlet(), which is in communication with the outlet path. When the liquid is made to flow by the pressure difference between the inletand the outlet, it is preferable to control the flow speed (mm/s) of the liquid to be 0.1 mm/s or more to 10.0 mm/s or less.

As illustrated in, the first recording sectionis configured to have the first liquid applying deviceand the conveying member, which conveys the recording medium. The reaction liquid and the ink are applied by the first liquid applying deviceto the desired positions of the recording medium, which is conveyed by the conveying member. The first reaction liquid applying deviceand the first ink applying devicereceive image signals of a recording data and apply the necessary reaction liquid and ink at each position. The second recording sectionis also configured to have the second liquid applying deviceand the conveying member, which conveys the recording medium, and applies the necessary reaction liquid and ink to each position in the same manner as the first recording section.illustrates the conveying memberin the form of a conveying roller, but it may be a spur, a belt, a supporting plate or the like as long as it has the function of conveying the recording medium.

The shape and size of the conveying membersat various locations in the apparatus can be set as appropriate depending on the location at which they are placed. In order to accurately convey the recording mediumin the form of a roll, it is preferable to place the conveying membersuch that the recording mediumis in a curved state, thereby keeping the recording mediumin a state where tension is moderately applied.

As illustrated in, the first heating sectionis configured to have the first heating deviceand the first conveying member. Similarly, the second heating sectionis configured to have the second heating deviceand the second conveying member. In the first heating sectionand the second heating sectionillustrated in, the recording mediumis conveyed with its recording surface facing downward in the vertical direction. The recording mediumto which the reaction liquid and the ink have been applied to record an image is heated by the first heating deviceand the second heating device, thereby evaporating liquid components of the image to dryness, while being conveyed by the first conveying memberand the second conveying member.

The first heating deviceand the second heating devicemay be of any configuration as long as they can heat the recording medium, and various conventionally known devices such as warm air dryers and heaters can be used. Among these, it is preferable to use a non-contact heater, such as electric wire heater or infrared heater, in terms of safety and energy efficiency. In addition, drying efficiency can be easily improved by using a mechanism that incorporates a fan and sends warm air for injecting heated gas onto the recording medium.

As for the method of heating, the recording mediummay be heated from the side of the surface to which the reaction liquid and the ink have been applied (recording surface (front surface)), may be heated from the back surface side or may be heated from both surfaces. The first conveying memberand the second conveying membermay be provided with a function of heating. It is preferable to set the heating temperature such that liquid components are quickly evaporated and the recording mediumis not over-dried from the viewpoint of suppressing its deformation. The temperature of the drying unit can be set so as to achieve the desired temperature of the recording medium based on conveying speed and ambient temperature.

Specifically, the temperature of the drying unit (such as warm air) is preferably set to 40° C. or higher to 100° C. or lower, and more preferably set to 60° C. or higher to 80° C. or lower. Also, when heating the recording mediumby blowing heated gas, the wind speed is preferably set to 1 m/s or more to 100 m/s or less. The temperature of the wind such as warm air can be measured using a K-type thermocouple thermometer. Specific examples of the measuring machine include the trade name “AD-H” (manufactured by A&D Company, Limited.).

The first cooling sectionis configured to have the first cooling memberand the first conveying member, and the second cooling sectionis configured to have the second cooling memberand the second conveying member(). The first cooling sectionand the second cooling sectioncool the recording medium, which has passed through the first heating sectionand the second heating sectionand has become hot. The first cooling memberand the second cooling membermay be of any configuration as long as they can cool the recording medium, and methods such as air cooling and water cooling can be used. Among these, it is preferable to blow unheated gas in terms of safety and energy efficiency. In addition, cooling efficiency can be easily improved by using a mechanism that incorporates a fan and blows air for injecting gas onto the recording medium. The temperature of the cooling unit can be set so as to achieve the desired temperature of an image on the recording medium based on conveying speed and ambient temperature. Specifically, the temperature of the cooling unit (such as blowing air) is preferably set to 20° C. or higher to 60° C. or lower, and more preferably set to 25° C. or higher to 50° C. or lower. When cooling by blowing gas, the wind speed is preferably set to 1 m/s or more to 100 m/s or less.

The recording mediumafter image recording is stored in the take-up section(). After recording is performed in the first recording section, the recording mediumpasses through the first heating sectionand the first cooling section.

Furthermore, after recording is performed in the second recording section, the recording mediumthat has passed through the second heating sectionand the second cooling sectionis conveyed by the conveying member. The recording mediumis finally stored in a state of being taken up in the form of a roll by the take-up device. Two or more take-up devicesmay be provided for, for example, storing different recorded matters, respectively.

For the laser die cutting apparatus as a laser light irradiating section (not illustrated) that irradiates the recording medium with laser light to cut it, a COlaser is usually used. By performing the irradiation with a high power COlaser, the materials in the laser beam path can be decomposed and evaporated, thereby cutting the recording medium. The laser die cutting apparatus may be arranged separately from the ink jet recording apparatus or may be connected in-line with the ink jet recording apparatus (that is, the ink jet recording apparatus may have the laser light irradiating section). If the ink jet recording apparatus has the laser light irradiating section, it is preferable that the laser light irradiating section is placed on the downstream side of the recording section with respect to the conveyance direction of the recording medium. For example, if the ink jet recording apparatus illustrated inis equipped with the laser light irradiating section, it is preferable that the laser light irradiating section is placed on the downstream side of the second cooling sectionand on the upstream side of the take-up devicewith respect to the conveyance direction of the recording medium.

The COlaser can be controlled to cut the recording medium by Q switching, which is a laser technology used to obtain intense pulsed light. Specifically, the Q switching frequency, Q release time and cut speed are controlled. It is preferable that the Q switching frequency is set to 5 kHz or more to 20 kHz or less, the Q release time to 10 us or more to 50 μs or less and the cut speed by laser light irradiation to 500 mm/s or more to 2,000 mm/s or less.

It is preferable that the spot diameter of the laser light is set to 0.1 mm or more to 0.4 mm or less. Also, if a cut region for cutting the recording medium is recorded by applying the reaction liquid and the ink, the line thickness (line width) of the cut region to be recorded is preferably 15% or more larger than the spot diameter of the laser light. By making the line width of the cut region larger in comparison with the spot diameter of the laser light, the narrowness and uniformity in cut width can be further improved. Note that the reaction liquid and the ink may be applied to the entire surface of the recording medium as a base.

Also, in the method for producing recorded matters, it is preferable that a cut region for cutting the recording medium is recorded in the step of recording the image and that the recording medium is cut by irradiating the cut region with the laser light in the step of cutting the recording medium.

By using the laser die cutting apparatus for irradiation with laser light, the recording medium can be cut and the desired part can be detached. Also, label paper including a label section provided with an adhesive layer on a resin film and release paper can be used as the recording medium, and only the label section can be cut and detached by irradiation with laser light, so-called half-cutting. When the half-cutting, the laser light is irradiated toward the surface of the recording medium on the side where the resin film exists. When half-cutting recording media, a difference in deformation amount when irradiated with laser light is likely to occur between a printed part to which a white ink has been applied, and a printed part to which a color ink has been applied and an unprinted part, and an expansion or a variation in cut width is noticeable. When half-cutting recording media, it is necessary to control the laser light so as not to affect the release paper, since only the label section is detached without detaching the release paper. In this case, it is considered that the cut width of a printed part to which a white ink, which is difficult to be decomposed and deformed by the laser light, has been applied is narrower, making the difference from the cut width of a printed part to which a color ink, which is easy to be decomposed and deformed by the laser light, has been applied and an unprinted part larger, resulting in a noticeable expansion or variation in cut width. In contrast, according to the method for producing recorded matters of the present invention, even when half-cutting recording media, high quality recorded matters with narrowly and uniformly aligned cut widths can be produced.

It is preferable that the amount of the ink applied to the region to be irradiated with the laser light (the region where the recording medium is cut) is set to 20 ng/600 dpi or more to 100 ng/600 dpi or less. The notation “ng/600 dpi” representing the amount of the ink applied represents the amount of the ink applied to 1 dot at a recording resolution of 600 dpi. By setting the amount of the ink applied to 20 ng/600 dpi or more, titanium oxide included in the region to be cut can suppress thermal deformation of the recording medium due to laser light irradiation and can further suppress the expansion and the variation in cut width. Also, by setting the amount of the ink applied to 100 ng/600 dpi or less, the recording medium can be firmly cut by laser light irradiation. In addition, it is preferable that an image or cut region to which an aqueous ink containing titanium oxide and an aqueous reaction liquid containing an inorganic metal salt are applied is recorded in the whole region irradiated with the laser light. In this way, a recording matter in which the cut edges are neatly aligned in the whole region can be obtained. However, an image or cut region using an aqueous ink containing titanium oxide and an aqueous reaction liquid containing an inorganic metal salt may not be recorded in a part of the region irradiated with the laser light as long as the appearance of the cut recording matter formed by cutting is not substantially impaired.

It is preferable that the amount of the reaction liquid applied is set to 0.05 times or more to 0.3 times or less in mass ratio to the amount of the ink applied. By making the amount of the reaction liquid applied in the above mass ratio to the amount of the ink applied, the reaction liquid can more effectively aggregate the ink and the amount of titanium oxide included in the region to be irradiated with the laser light (the region to be cut) can be controlled to be more uniform. This enables even higher quality ink jet-recorded matters with more narrowly and uniformly aligned cut widths to be produced.

The method for producing recorded matters of the present invention has a step of applying an aqueous reaction liquid to a recording medium (reaction liquid applying step). This reaction liquid applying step is preferably carried out before an ink applying step.

The reaction liquid reacts with the ink by coming into contact with the ink, to aggregate components (components having anionic groups, such as a resin, a surfactant, or a self-dispersible pigment) in the ink, and contains a reactant. The presence of a reactant can destabilize the state of existence of the components having anionic groups in the ink and promote aggregation of the ink when the ink and the reactant come into contact on the recording medium. Examples of the reactant include a cationic component such as a polyvalent metal ion and a cationic resin, as well as an organic acid. The reactant may be used alone or in combination two or more.

Examples of the polyvalent metal ion that constitutes a polyvalent metal salt include a divalent metal ion such as Ca, Cu, Ni, Mg, Sr, Baand Zn, and a trivalent metal ion such as Fe, Cr, Yand Al. In order to make the reaction liquid contain a polyvalent metal ion, a water-soluble polyvalent metal salt (which may be a hydrate) formed by bonding of a polyvalent metal ion and an anion can be used. Examples of the anion include an inorganic anion such as Cl, Br, I, ClO, ClO, ClO, ClO, NO, NO, SO, CO, HCO, PO, HPOand HPO; and an organic anion such as HCOO, (COO), COOH(COO), CHCOO, CHCH(OH)COO, CH(COO), CHCOO, CH(COO)and CHSO.

The reaction liquid used in the method for producing recorded matters of the present invention contains an inorganic metal salt. As the inorganic metal salt, it is preferable to use a polyvalent metal salt formed by bonding of the above-described polyvalent metal ion and inorganic anion. The inorganic metal salt is difficult to burn and disappear even when irradiated with laser light and heated to a high temperature. Therefore, by applying in advance the reaction liquid containing an inorganic metal salt to the region to be cut, thermal deformation of the recording medium at the time of laser light irradiation can be suppressed and the narrowness and uniformity in cut width can be improved.